Aperture: Vaults may be substantially smaller than the library

When you create a vault to back up your Aperture library, you may notice that sometimes the vault is substantially smaller than the library. Learn why your vault may be smaller.

The number of image versions in your projects will affect the size of a vault. The more versions you create per master, the smaller a vault will be in comparison to your library. Database files that deal with versions' thumbnails and previews are in the Aperture library but are not included in a vault. Restoring from a vault rebuilds these files dynamically. If your workflow involves creating a large number of versions, then your vault will be smaller in comparison to your library.

Plug-ins are not stored in the library but are included a vault backup. If you have a large number of plug-ins, your vault size will grow relative to the library.